Carpets used in automobiles as a floor coating are essentially needled carpets of the “flat needled fabrics” or “Dilour™” needled carpets.
These carpets belong to the family of non-wovens. They are preferred to woven traditional coatings, since they are deformable and may fit the shapes of floorings of vehicles.
The “Dilour™” needled carpets are also called “velvet needled carpets” because of their surface aspect. This velvet consists of randomly distributed fibers. These fibers may be in the form of individual tufts or fibers.
These carpets are formed from a web of non-woven fibers, for example made by carding-lapping. The web undergoes a needling operation, or “dilourage”, consisting of partly pulling fibers out of the web in order to form loops at the surface of said web.
The needling is for example carried out on a “Dilour™” machine consisting of a conveyor equipped with a set of brushes and a needling head equipped with needle boards. The needles carry away a portion of the fibers of the web as far as the interior of the brushes of the conveyor, over a depth which will correspond to the height of the velvet of the finished product.
Simultaneously with the making up of the velvet, the needling densifies the web by contributing to the entanglement of the fibers in the portion of the web called “sole”, lying on the surface of the brushes. The thickness of the sole is gradually reduced as the fibers are entangled.
At the end of this needling operation, or dilourage, a tufted velvet is obtained. The latter may then undergo a shearing operation aiming at cutting the top of the loops in order to obtain a velvet consisting of individual fibers.
Such a sheared velvet, or shaved velvet, is always easier to clean than a tufted velvet. Indeed, the shape of the loops provides better adhesion to small size solid wastes, such as plants wastes or gravels.
However, the shearing operation has a non-negligible cost since it is technically difficult to put a clipper in line behind a “Dilour™” machine. Further, the shearing generates between 5% and 10% of loss of the engaged material.